Apparatus for enameling surfaces of refractory materials.



No 669,567. Patented Mar. l2, I90l. c. n. wusmuu.

APPARATUS FOR ENAIIELING SURFACES 0F REFRACTORY MATERIALS.

(Applimdon filed Apr. 25, 1899.)

( No Model.)

H I IVY Kxmm-Mvx UNITED STATES PATENT @rrrcn CHARLES H. WATERMAN, OFPOMPTON PLAINS, NEW? JERSEY.

APPARATUS FOR ENAMELING SURFACES 0F REFRACTORY MATERIALS.

SPECIFICATION forming part of Letters Patent No. 669,567, dated March12, 1901.

Application filed April 2 5 l 8 9 9.

To all whom it may concern:

Be it known thatI, CHARLES H. WATERMAN, a citizen of the United States,residing at Pompton Plains, Morris county, and State of New Jersey, haveinvented certain new and useful Improvements in Apparatus for Enamelingthe Surfaces of Refractory Materials, of which the following is aspecification sufficient to enable others skilled in the art to whichthe invention appertains to make and use the same.

My invention relates to the art of enameling the surfaces of materialswhich are, relatively speaking, non-conductors of heat and electricity,such as those containing silicate of aluminium, as distinguished fromarticles composed of metal or other material of comparatively highconductivity.

My improvements are especially adapted to the enameling of the faces ofbricks,tiles,and other articles of clay. In the enameling of bricks,&c., it has heretofore been customary to place three or four, with theenamelingmaterial applied thereto, in a muffler, a suitable number ofmufflers being placed in a furnace, and the whole heated gradually forseveral days. The enameling material, being primarilyin a soft state, isunder these conditions apt to be discolored more or less by the productsof combustion emanating from the fuel used. Furthermore, it ispractically impossible to control the degree of heat or attain a uniformdistribution thereof, so that results are uncertain,and the defectivepieces usually average at least one-third of those treated. The bricksalso become thoroughly and uniformly heated throughout, which isobjectionable, as it is well known that bricks cannot be reheat-edWithout danger of deteriora tion, and the same is true to a greater orless extent of articles made from even the finer clays. The continuedcontraction of the clay long after the enamel has set and cooled alsotends to crack or crease the enamel, From fifteen to eighteen days arerequired in firing and cooling, to say nothing of the labor and expenseinvolved.

The main object of my invention is designed to aiford adequate means forthe fusion of enameling material onto the surfaces to which it isapplied While the body of the article is relatively cool, according tothe process set forth Serial No. 714,379. (No model.)

in my Letters Patent No. 6403M, dated January 9, 1900, the applicationfor which was a subdivision of the present application,the object beingto avoid the crazing of the enamel,that would otherwise result from thedifference in contractibility, to avoid the lo s from deterioration orfracture heretofore in volved in enameling surfaces by reason of theretiring and reheating of the body of the article to the temperaturerequired to fuse the enamel, as Well as the deleterious effects upon theenamel of the presence of products of combustion, such as discoloration,impaired surface, the. By my apparatus I furthermore simplify andquicken the manipulation involved in the art of enameling, and therebymaterially cheapen the cost of the product commercially, While affordinga superior article of manufacture.

My invention consists in the means herein described and claimed forflashing or quickly fusing enameling material onto the surface of anarticle of clay or other material of comparatively low conductivity asregards heat and electricity by exposing the said surface, with theenameling material applied thereto, in proximity to, but Without contactwith, an electric converter heated by an electric current to asufficiently high temperature to fuse the enamel, the heat being applieddirectly to the enameling material in a plane parallel thereto in suchmanner as to penetrate through said enameling material before reachingthe surface to which it is to be fused, whereby I am enabled to flash oreffect the adhesion of the enamel over the entire underlying surfacewhile the body of the article is comparatively cool, and then effect theremoval of the article before the mass of material of which it iscomposed becomes unduly, unnecessarily, or dangerously heated and whilepractically and relatively cold. As a result the integrityof the articleboth in form and structure is retained unimpaired, and the enamel afterit has set is not distorted, cracked, or crazed by the subsequentshrinkage or contraction of the article, neither is the surface of theenamel contaminated by products of combustion. A special feature of myinvention in this connection consists in the interposition between theelectric heater and the surface of the article to be enameled of anon-oxidizable shield for the purpose of intercepting any particles thatmay be given off by the electric converter during use-as, for instance,where carbon is used as a medium of resistance in attaining therequisite degree of electrical heat. Thus by the use of electricity as aheat medium lam enabled to quickly attain a comparativelyhigh degree ofuniform electrical heat in a converter having a comparatively largeextension of heating-surface, the heat being uniform over the whole areathereof and under perfect control, so that the enamel and the underlyingsurface are raised to the requisite degree of temperatu re withoutexposing the other surfaces of the article to direct radiationor theenamel to contamination by reason of particles given off by theconverter. By thus heating the surface underneath the enamel only to arelatively high degree of heat by direct radiation I avoid the harmfuleffects heretofore resulting from the difference in contractibilitybetween the enamel and the mass of material, to one surface of. which itis applied.

In the accompanying drawings, Figure l is a transverse section of anelectric furnace adapted to the enameling of tiles, bricks, and likearticles. Fig. 2 is a longitudinal section of the same; Fig. 3, a Viewsimilar to Fig. 1, showing a non-oxidizable shield interposed betweenthe converter and the articles to be enameled.

In the drawingsmhich are mainly symbolic, I show an electric converteror heater 0 as consisting of a plate-say of carbon or any suitablematerial affording the desired electric resista-nce-interposed betweenand connected to the terminals P and N of an electric circuit connectedwith a suitable source of electricity G.

I prefer to inclose the electric heater or converter O in a furnace ormuffle F, of refractory material, and to extend such furnace or mufflein either direction considerably beyond the position of the converter C,under which the actual fusion of the enam cling material takes place.The articles B to be enameled are presented successively to the actionof the electric converter C by any appropriate mechanical expedient, asby means of movable platforms M. Thus the platforms may consist of aseries of cars or trucks upon the longitudinal rails r r, the trucksbeing coupled together or to a cable m, or an endless belt or chainplatform, of refractory non-combustible material may be substituted, ifdesired. The top of the furnace F is preferably made with one or moremovable sections F for convenience of access, and the furnace or wallsof refractory material preferably extend beyond the electric converter Oa distance su fficient to admit of thegradual cooling of the articlestreated before removal.

The electric converter 0 may be made of any suitable medium affording arelatively high degree of resistance to the electric current, as beforeintimated. lVherc a carbon plate is used for the purpose, I interposebetween it and the surfaces to be enameled a shield S, of non-oxidizablematerial, capable of resisting while transmitting a ielatively highdegree of heat. This is for the purpose of intercepting particles ofcarbon that may be given off by the electrical converter under theaction of the electric current and may be effected by suspending theplate S, of platinum or other suitable material, as in Fig. 3, betweenthe electric converter (3 and the means for presenting the surfaces tobe enameled by the electric heat generated in the converter 0 or byplating or otherwise covering the converter with a suitablenon-oxidizable material.

Vents p 22 may be provided for the escape of carbon dioxid or other gasgenerated in the furnace, and the usual window for inspection may beinserted in the wall of said furnace or mufiie.

The enameling material is applied to the surfaces to be enameled priorto subjecting them to the action of electric heat emanating from theconverter O in any suitable or wellknown manner, and the articles arepresented to the electrical converter C continuously or intermittently,as may be desired.

lVhat I claim as my invention, and desire to secure by Letters Patent,is

1. In apparatus for flashing enamel upon the surface of refractorymaterial, the combination of an electrical converter having a broadheating-surface, and mechanism for presenting a surface of refractorymaterial in a plane parallel to said heating-surface in proximitythereto but out of contact therewith, whereby the enamel is immediatelyfused to the surface of refractory material upon which it is imposed bya uniform degree of electric heat applied simultaneously andinstantaneously over all parts of the enamel, substantially as hereinset forth.

2. In apparatus for flashing enamel upon the surface of refractorymaterial, the combination of. an electrical converter having a broadheating-surface, walls of refractory material inclosing said electricalconverter, and mechanism for presenting a surface of refractory materialin a plane parallel to said heat-- ing-surface, in proximity thereto butout of contact therewith, whereby the enamel is immediately fused to thesurface of refractory material upon which it is imposed by a uniformdegree of electric heat applied simultaneously and instantaneously overall parts of the enamel, substantially as herein set forth.

3. In apparatus for flashing enamel upon the surface of refractorymaterial, the combination of an electrical converter having a broadheating-surface,walls of refractory material inclosing said electricalconverter, a non-oxidizable shield interposed between said electricconverter and the surface to be enameled, and mechanism for presenting asurover all parts of the enamel and the latter is I protected fromcontamination by contact with emanations from the electrical converter,sub- 10 stantially as herein set forth.

CHAS. H. l/VATERMAN.

Witnesses:

GEO. WM. MIATT, D. W. GARDNER.

